Brining beef works great. That's how you make corned beef, pastrami, etc. There is so much flavor in beef that brining isn't necessary IMO unless you are making corned beef or pastrami.

I prefer injecting beef instead using something as simple as rub in beef broth. Adding melted butter to the injection is interesting too, creole butter is one example. I do this a lot. Only do the butter thing though if you are throwing it right on the smoker.